Author(s):
ROSNAH ISMAIL*; ROILA AWANG* and HAZIMAH, A H*

Palm dihydroxystearic acid (DHSA) is derived by catalytic reaction from palm oil-based or palm kernel oil-based oleic acid, vegetal renewable sources of many interesting ingredients. Once crystallised, the product is off-white in colour, tasteless with a slight acid smell and is non-irritant to the skin. The DHSA structure is peculiar as it contains a carboxyl group and two hydroxyl groups at the 9 and 10 positions of the C18 carbon chain. Such structure leads to many interesting applications. When used in cosmetics, it significantly changes the properties of oily phases and wax gels. It can also interact strongly with the solid surfaces of pigments and inorganic fillers, leading to better colour development, long lasting skin adhesion- and better pay-off properties. Such a combination of properties and effects lead to many interesting applications particularly for cosmetics. As an additive in a transparent soap formulation, DHSA has been found to enhance the transparency of the soap. Besides, DHSA is also a potential feedstock for various derivatives through substitution reactions onto one, two or all three reactive sites. Some alkyl esters from DHSA have been studied, which show exceptional skin feel and powder binding capability. Metallic soaps of DHSA have shown pigment coating capability and a set of different properties when compared to the usual metallic stearates. Many more derivatives such as monoglycerides, estolides, alkanoamides, have been derived from DHSA to exploit all the possible derivatisation potential of DHSA. Hence, the aim of this article is to review all the works on palm DHSA that have been done so far in the Malaysian Palm Oil Board (MPOB) under the purview of the value addition strategy.